Is Windows 10 dropping an upgrade error 0x800704CF (during upgrade, during App launch, during accessing a Microsoft account etc.)? This blog post presents a few hints to analyze this error.
I was noticed about error 0x800704CF the first time in German MS-Answers forum. A user wasn't able to use the Calendar app after upgrading from Windows 8.1 to Windows 10. But I've seen this error in other forum posts (accessing beta version of Windows store, during Windows 10 upgrades etc.). Error 0x800704CF stands for "The network location cannot be reached" – something went wrong during a network or internet access attempt.
Are Windows components are damaged?
If the error occurs, it's a good idea to assure, that it's not caused by a third party tool like antivirus software, installed on the system. Uninstall those tools und use the clean/removal tools provided by vendors to clean files and registry entries left after uninstalling. See also my blog post Windows 10 Anniversary Update – FAQ and Tips.
Also take care, that Windows itself isn't damaged and contains corrupt system files. Have a look at my article Check and repair Windows system files and component store and execute the following command in an administrative command prompt window:
dism /online /cleanup-image /startcomponentcleanup
Check Proxy settings
Installed security software, malware or similar programs can alter Windows proxy settings and is causing trouble with apps and updates. So reset your proxy settings in Internet Explorer (see KB2289942).
Faulty network adapters and protocols
If the checks listed above didn't help, check your network configuration. This MS Answers foreum thread (Windows 7) identified an unchecked network property "Client for Microsoft Network" as a root cause. Here (deleted) and here phantom network adapter entries was the reason for this error. Deleting those entries fixed the issue.
Wrong TLS settings
I found this German forum entry, where the error occurs during login. Faulty TLS settings has been identified as a root cause. Fire up Internet Explorer and go to Internet options – then check 'Use TLS 1.0, TLS 1.1 and TLS 1.2' on Extra tab. If that doesn't helps, try to analyze the log files recorded from Windows.
Cookies helps to fund this blog: Cookie settings